"It's all she talks about," Sidney's mom, Jamie Scheetz, told NHL.com after the encounter with Crosby. "It changed her whole day, her whole week."
The video, shared by the Penguins on their social media channels, has been making the rounds.
"'Mommy I'm going viral,' she kept saying," Jamie said.
The younger Sidney -- and yes, we know what you are thinking, she is not named after Crosby despite the Scheetz's Penguins fandom; Jamie just always liked the name -- takes skating lessons at UPMC Lemieux Sports Complex, the same site as the Penguins training facility. Occasionally the team will be practicing after Sidney completes her clinic.
"I had told her I didn't know if we could watch practice and that we didn't have a lot of time that day," said Jamie.
But she would end up being happy they stayed.
Crosby noticed young Sidney -- in her standard skating lessons outfit which consists of a black Crosby No. 87 jersey and pants -- sitting a few rows behind the glass watching practice.
"He tapped the glass and shortly after I saw him scooping up the puck," Jamie said. "She was a little shy but she went to say thank you and he said, 'You're welcome.' Afterwards, I realized we should have congratulated him on his 500th goal."
On the night of Crosby's milestone, Sidney, older brothers Mason, 10, and Maddox, 8, were in front of the television in their jerseys to witness history.